Initial firmware commit.

firmware/common/jtag.hpp

@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
+ *
+ * This file is part of PortaPack.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __JTAG_H__
+#define __JTAG_H__
+
+#include <cstdint>
+#include <cstddef>
+
+#include <bitset>
+
+namespace jtag {
+
+class Target {
+public:
+	using bit_t = uint_fast8_t;
+
+	virtual ~Target() {
+	}
+
+	virtual void delay(const size_t n) = 0;
+	virtual jtag::Target::bit_t clock(
+		const jtag::Target::bit_t tms_value,
+		const jtag::Target::bit_t tdi_value
+	) = 0;
+};
+
+class JTAG {
+public:
+	constexpr JTAG(
+		Target& target
+	) : target(target)
+	{
+	}
+
+	void reset() {
+		/* ??? -> Test-Logic-Reset */
+		for(size_t i=0; i<8; i++) {
+			target.clock(1, 0);
+		}
+	}
+
+	void run_test_idle() {
+		/* Test-Logic-Reset -> Run-Test/Idle */
+		target.clock(0, 0);
+	}
+
+	void runtest_tck(const size_t count) {
+		target.delay(count);
+	}
+
+	uint32_t shift_ir(const size_t count, const uint32_t value) {
+		/* Run-Test/Idle -> Select-DR-Scan -> Select-IR-Scan */
+		target.clock(1, 0);
+		target.clock(1, 0);
+		/* Scan -> Capture -> Shift */
+		target.clock(0, 0);
+		target.clock(0, 0);
+
+		const auto result = shift(count, value);
+
+		/* Exit1 -> Update */
+		target.clock(1, 0);
+		/* Update -> Run-Test/Idle */
+		target.clock(0, 0);
+
+		return result;
+	}
+
+	uint32_t shift_dr(const size_t count, const uint32_t value) {
+		/* Run-Test/Idle -> Select-DR-Scan */
+		target.clock(1, 0);
+		/* Scan -> Capture -> Shift */
+		target.clock(0, 0);
+		target.clock(0, 0);
+
+		const auto result = shift(count, value);
+
+		/* Exit1 -> Update */
+		target.clock(1, 0);
+		/* Update -> Run-Test/Idle */
+		target.clock(0, 0);
+
+		return result;
+	}
+
+	template<size_t N>
+	void shift_dr(std::bitset<N>& bits) {
+		/* Run-Test/Idle -> Select-DR-Scan */
+		target.clock(1, 0);
+		/* Scan -> Capture -> Shift */
+		target.clock(0, 0);
+		target.clock(0, 0);
+
+		for(size_t i=0; i<bits.size(); i++) {
+			bits[i] = target.clock(
+				(i == (bits.size() - 1)) ? 1 : 0,
+				bits[i]
+			);
+		}
+
+		/* Exit1 -> Update */
+		target.clock(1, 0);
+		/* Update -> Run-Test/Idle */
+		target.clock(0, 0);
+	}
+
+private:
+	Target& target;
+
+	uint32_t shift(const size_t count, uint32_t value);
+};
+
+} /* namespace jtag */
+
+#endif/*__JTAG_H__*/